When reading the first statement from the dossier of the Flemish greens I had the impression that the author avoided to name of the phenomenon he described. When reading the next two statements I had the exact same impression. They were made by investigators of the Potsdam-Institut für Klimafolgenforschung (PIK) who cited two studies about atmospheric changes. They describe the impact of the Arctic Oscillation on our weather, but carefully avoided its name. In stead they make the “suggestion” that global warming (by warming the Arctic region) changes these “waves” and therefor was (partly) the cause wintry weather we got.
The first statement is from Jaiser et al. The second from Petoukhov et al. I could trace this last one back to: Weather extremes provoked by trapping of giant waves in the atmosphere by Petoukhov et al.
They seem to explain the cold weather by blocking events in the higher atmosphere partly caused by the warming of the Arctic. I could agree with the blocking event causing our rather cold weather. As far as I can know it was seen as the common cause for the heat wave in Russia 2010, the Pakistan flood in 2010 and the heat wave in the United States in 2011. I think it is a known meteorologic process.
What about the human attribution?
[…] the suggested physical process increases the probability of weather extremes, but additional factors certainly play a role as well, including natural variability. […]
To be fair, they say it increases the probability of extremes and that natural variability plays a role. In the paper they calculated the wave motions and tested when they grind to a halt of amplify. Okay, but this part catched my attention (my bold):
[…] Also, the 32-year period studied in the project provides a good indication of the mechanism involved, yet is too short for definite conclusions. […]
A 32 year period (the research was sent for review in June 2012) means the start of their investigations was around 1980. Just at the beginning of a warm cycle and excluding all the data of the previous cool cycle… Indeed, this is a bit short to draw conclusions from.
Even if they describe their paper as a breakthrough and they seem to be very sure about human attribution, the conclusion doesn’t seem to be clearcut in favor of human attribution (my bold):
[…]If the observed increasing number of summer months with high-amplitude wave numbers m=6, 7, and 8 indeed is the result of ongoing global warming, then we have described a possible dynamical mechanism for how global warming might contribute to future extreme summer events.[…]
While the described processes seem plausible, they don’t seem to prove human attribution and again produced AFTER the facts. In a way, I don’t have a problem with the theory, nor with the adjusting. A theory can be adjusted when the observations don’t fit the theory anymore. But this is different. Over time, the original idea morphed into something completely different. And yes, also this time they found a nice explanation, but it is slowly changing the theory into something different in order to be able to adjust the theory. It also became something non-falsifiable. There is no condition, no weather event that could falsify the theory.
But there seems to be at least one other theory that predicted these new observations in advance. Since I got interested about climate, I learned that climate comes in cycles. It was not uncommon to read that a cooling period was ahead. This because of several cycles that would go negative together, but also a sun that went to sleep and volcanic activity as a possible amplifier. At that time it seemed a bit ridiculous to hear about, but after a while it made sense. In that light the current stagnation/cooling was no real surprise to me. This of course doesn’t mean it is necessarily true, but it gives an indication that it probably is well founded. I have more confidence in a theory that predicted the observations all along, than in a theory that has to be adjusted every time observations change.
Why are we so hooked to a theory that seems to be wrong every time the observation changes? And yet we seem to stay confident in it…
Trust, yet verify 